%I #5 Mar 30 2012 18:58:07
%S 0,0,1,1,2,8,35,403,18020,7924920,146015988543,1159796524860801383,
%T 169358027383278750824815637192,
%U 196420876345386921523978742421837032517974708496
%N a(n)=f(a(n-1),a(n-2)+1,a(n-3)), where f(x,y,z)=yz+zx+xy and (a(1),a(2),a(3))=(0,0,1).
%C For a guide to related sequences, see A203761.
%t a[1] = 0; a[2] = 0; a[3] = 1;
%t a[n_] := SymmetricPolynomial[2, {a[n - 1], 1 + a[n - 2], a[n - 3]}]
%t Table[a[n], {n, 1, 16}] (* A203762 *)
%Y Cf. A203761.
%K nonn
%O 1,5
%A _Clark Kimberling_, Jan 07 2012